Articulated vehicles having two connected parts, each part having a fixed, driven axle supporting two road wheels, where the angle between the two parts may be altered in order to steer the vehicle are used in a variety of construction and mining applications, amongst others. The vehicles are well suited to use on difficult terrain. The two parts of the vehicle are connected by a joint which allows the parts to pivot about a vertical axis to enable the vehicle to be steered, and about a longitudinal axis which enables the two parts of the vehicle to roll relative to one another which helps to keep the wheels in contact with the ground.
An engine is provided in one part of the vehicle and drive to the wheels of the other part is transmitted from the engine to the other part via a propeller shaft which accommodates movement between the two parts of the vehicle. The propeller shaft extends generally longitudinally between the two parts. It is provided with two universal joints and a sliding joint and connected to a differential on an axle of one of the parts so as to drive wheels mounted to half shafts extending from the differential in a direction substantially perpendicular to the propeller shaft.
The various joints required in the propeller shaft make the arrangement relatively complex and costly, making an articulated construction uneconomic for smaller, and particularly pedestrian, vehicles where the market demands a lower cost. Also, torque reaction through the propeller shaft when the vehicle is driven causes the two parts of the vehicle to roll relative to one another and this can make the vehicle difficult to control. This can be a greater problem for smaller lightweight vehicles.
Embodiments of the present invention have been made in consideration of these problems.